1
2
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4
5
6#include <linux/refcount.h>
7
8#ifndef _L2TP_CORE_H_
9#define _L2TP_CORE_H_
10
11#include <net/dst.h>
12#include <net/sock.h>
13
14#ifdef CONFIG_XFRM
15#include <net/xfrm.h>
16#endif
17
18
19#define L2TP_TUNNEL_MAGIC 0x42114DDA
20#define L2TP_SESSION_MAGIC 0x0C04EB7D
21
22
23#define L2TP_HASH_BITS 4
24#define L2TP_HASH_SIZE BIT(L2TP_HASH_BITS)
25
26
27#define L2TP_HASH_BITS_2 8
28#define L2TP_HASH_SIZE_2 BIT(L2TP_HASH_BITS_2)
29
30struct sk_buff;
31
32struct l2tp_stats {
33 atomic_long_t tx_packets;
34 atomic_long_t tx_bytes;
35 atomic_long_t tx_errors;
36 atomic_long_t rx_packets;
37 atomic_long_t rx_bytes;
38 atomic_long_t rx_seq_discards;
39 atomic_long_t rx_oos_packets;
40 atomic_long_t rx_errors;
41 atomic_long_t rx_cookie_discards;
42 atomic_long_t rx_invalid;
43};
44
45struct l2tp_tunnel;
46
47
48struct l2tp_session_cfg {
49 enum l2tp_pwtype pw_type;
50 unsigned int recv_seq:1;
51 unsigned int send_seq:1;
52 unsigned int lns_mode:1;
53
54
55 u16 l2specific_type;
56 u8 cookie[8];
57 int cookie_len;
58 u8 peer_cookie[8];
59 int peer_cookie_len;
60 int reorder_timeout;
61 char *ifname;
62};
63
64
65
66
67
68
69#define L2TP_SESSION_NAME_MAX 32
70struct l2tp_session {
71 int magic;
72 long dead;
73
74 struct l2tp_tunnel *tunnel;
75 u32 session_id;
76 u32 peer_session_id;
77 u8 cookie[8];
78 int cookie_len;
79 u8 peer_cookie[8];
80 int peer_cookie_len;
81 u16 l2specific_type;
82 u16 hdr_len;
83 u32 nr;
84 u32 ns;
85 struct sk_buff_head reorder_q;
86 u32 nr_max;
87 u32 nr_window_size;
88 u32 nr_oos;
89 int nr_oos_count;
90 int nr_oos_count_max;
91 struct hlist_node hlist;
92 refcount_t ref_count;
93
94 char name[L2TP_SESSION_NAME_MAX];
95 char ifname[IFNAMSIZ];
96 unsigned int recv_seq:1;
97 unsigned int send_seq:1;
98 unsigned int lns_mode:1;
99
100
101 int reorder_timeout;
102 int reorder_skip;
103 enum l2tp_pwtype pwtype;
104 struct l2tp_stats stats;
105 struct hlist_node global_hlist;
106
107
108
109
110
111
112 void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
113
114
115
116
117
118
119
120 void (*session_close)(struct l2tp_session *session);
121
122
123
124
125
126
127 void (*show)(struct seq_file *m, void *priv);
128
129 u8 priv[];
130};
131
132
133struct l2tp_tunnel_cfg {
134 enum l2tp_encap_type encap;
135
136
137 struct in_addr local_ip;
138 struct in_addr peer_ip;
139#if IS_ENABLED(CONFIG_IPV6)
140 struct in6_addr *local_ip6;
141 struct in6_addr *peer_ip6;
142#endif
143 u16 local_udp_port;
144 u16 peer_udp_port;
145 unsigned int use_udp_checksums:1,
146 udp6_zero_tx_checksums:1,
147 udp6_zero_rx_checksums:1;
148};
149
150
151
152
153
154
155
156#define L2TP_TUNNEL_NAME_MAX 20
157struct l2tp_tunnel {
158 int magic;
159
160 unsigned long dead;
161
162 struct rcu_head rcu;
163 spinlock_t hlist_lock;
164 bool acpt_newsess;
165
166
167 struct hlist_head session_hlist[L2TP_HASH_SIZE];
168
169 u32 tunnel_id;
170 u32 peer_tunnel_id;
171 int version;
172
173 char name[L2TP_TUNNEL_NAME_MAX];
174 enum l2tp_encap_type encap;
175 struct l2tp_stats stats;
176
177 struct list_head list;
178 struct net *l2tp_net;
179
180 refcount_t ref_count;
181 void (*old_sk_destruct)(struct sock *sk);
182 struct sock *sock;
183 int fd;
184
185
186
187 struct work_struct del_work;
188};
189
190
191struct l2tp_nl_cmd_ops {
192
193
194
195
196
197
198 int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
199 u32 session_id, u32 peer_session_id,
200 struct l2tp_session_cfg *cfg);
201
202
203
204
205
206
207 void (*session_delete)(struct l2tp_session *session);
208};
209
210static inline void *l2tp_session_priv(struct l2tp_session *session)
211{
212 return &session->priv[0];
213}
214
215
216void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel);
217void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel);
218void l2tp_session_inc_refcount(struct l2tp_session *session);
219void l2tp_session_dec_refcount(struct l2tp_session *session);
220
221
222
223
224
225struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
226struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth);
227struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel,
228 u32 session_id);
229
230struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id);
231struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
232struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
233 const char *ifname);
234
235
236
237
238
239int l2tp_tunnel_create(int fd, int version, u32 tunnel_id,
240 u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
241 struct l2tp_tunnel **tunnelp);
242int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
243 struct l2tp_tunnel_cfg *cfg);
244void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel);
245
246struct l2tp_session *l2tp_session_create(int priv_size,
247 struct l2tp_tunnel *tunnel,
248 u32 session_id, u32 peer_session_id,
249 struct l2tp_session_cfg *cfg);
250int l2tp_session_register(struct l2tp_session *session,
251 struct l2tp_tunnel *tunnel);
252void l2tp_session_delete(struct l2tp_session *session);
253
254
255
256
257
258void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
259 unsigned char *ptr, unsigned char *optr, u16 hdrflags,
260 int length);
261int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
262
263
264void l2tp_session_set_header_len(struct l2tp_session *session, int version);
265int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb);
266
267
268
269
270
271int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, const struct l2tp_nl_cmd_ops *ops);
272void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type);
273
274
275int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg);
276
277
278
279
280struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk);
281
282static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
283{
284 switch (session->l2specific_type) {
285 case L2TP_L2SPECTYPE_DEFAULT:
286 return 4;
287 case L2TP_L2SPECTYPE_NONE:
288 default:
289 return 0;
290 }
291}
292
293static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel)
294{
295 struct dst_entry *dst;
296 u32 mtu;
297
298 dst = sk_dst_get(tunnel->sock);
299 if (!dst)
300 return 0;
301
302 mtu = dst_mtu(dst);
303 dst_release(dst);
304
305 return mtu;
306}
307
308#ifdef CONFIG_XFRM
309static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
310{
311 struct sock *sk = tunnel->sock;
312
313 return sk && (rcu_access_pointer(sk->sk_policy[0]) ||
314 rcu_access_pointer(sk->sk_policy[1]));
315}
316#else
317static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
318{
319 return false;
320}
321#endif
322
323static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb,
324 unsigned char **ptr, unsigned char **optr)
325{
326 int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
327
328 if (opt_len > 0) {
329 int off = *ptr - *optr;
330
331 if (!pskb_may_pull(skb, off + opt_len))
332 return -1;
333
334 if (skb->data != *optr) {
335 *optr = skb->data;
336 *ptr = skb->data + off;
337 }
338 }
339
340 return 0;
341}
342
343#define MODULE_ALIAS_L2TP_PWTYPE(type) \
344 MODULE_ALIAS("net-l2tp-type-" __stringify(type))
345
346#endif
347